This invention relates to a backflow preventer.
Backflow preventers are principally used for preventing contamination of a public water distribution system by preventing backflow or back-siphonage of contaminated water into the system. Usually, the backflow preventer assembly is installed in a pipeline between a main supply line and a service line that feeds an installation, e.g., hotels, factories or other institutions, or even a multi or single family residence. A backflow preventer assembly typically includes two check valves permitting flow only in the direction from the main supply line to the service line.